Environmental Engineering Reference
In-Depth Information
Corrective actions:
Adjust belt speed; change conditioning
chemical; adjust chemical dosage; clear spray nozzles and adjust
sprays; replace belt.
•
Belt wear along the edges in belt press is excessive.
Causal factors:
Roller misalignment; improper belt tension; ten-
sion or alignment system control malfunction
Corrective actions:
Correct roller alignment; correct tension;
repair tracking and alignment system controls.
symptom 13.
•
symptom 14.
Belt shifts or seizes in belt press.
Causal factors:
Uneven sludge distribution; inadequate or uneven
belt washing
Corrective actions:
Adjust feed for uniform sludge distribution;
clean and adjust belt-washing sprays.
10.7.3.2 Filter Press Process Control Calculations
As part of the operating routine for filter presses, operators are
called upon to make certain process control calculations. The process
control calculation most commonly used in operating the belt filter
press determines the hydraulic loading rate on the unit. The most com-
monly used process control calculation used in the operation of plate-
and-filter presses determines the pounds of solids pressed per hour.
Both of these calculations are demonstrated below.
10.7.3.2.1 Belt filter Press hydraulic loading rate
Example 10.28
Problem:
A belt filter press receives a daily sludge flow of 0.30 gal. If the
belt is 60 in. wide, what is the hydraulic loading rate on the unit in gal-
lons per minute for each foot of belt width (gpm/ft)?
Solution:
1,000,000 gal
1MG
1day
1440 mi
0.30 MG
1day
208.3 gal
1min
1ft
12 in.
×
×
=
;
60 in.
×
=
5ft
n
208
.3 gal
5ft
=
41.7 gpm/ft
10.7.3.2.2 Pounds of Solids Pressed Per hour in Plate-and-frame Press
Example 10.29
Problem:
A plate-and-frame filter press can process 850 gal of sludge
during its 120-min operating cycle. If the sludge concentration is 3.7%,
and if the plate surface area is 140 ft
2
, how many pounds of solids are
pressed per hour for each square foot of plate surface area?
